--- "D. Richard Hipp" <[EMAIL PROTECTED]> wrote: > Peter Bartholdsson wrote: > > Think the topic explains it but there any way to enable recursive > triggers? > > Aka, triggers that run as result of a change by a trigger. > > > > Recursive triggers are on the todo list. They are a prerequisite > for the planned implementation of foreign keys. > > One stubling block with recursive triggers is that a recursive > trigger can result in an infinite loop. I sent out a query a > month or so ago requesting ideas on how to detect and deal with > infinite loops in recursive triggers. I got a few helpful > responses. More input would be appreciated.
I believe this is roughly equivalent to deadlock. It should best be dealt with in the same manner. That said, the simplest way to handle it is limiting the depth of recursion. It's simple to implement using a counter. The drawback being the user must calculate and set the depth. A more flexible option might just be to let the limit on resources handle it. Memory limits will set the upper bound on recursion. As long as you can gracefully handle and recover from that condition it should be fine. There are more complicated solutions but I personally doubt they're worth the effort. ===== --------------------------------- "Lord Tarlington gazed upon the crazed Egyptian hieroglyphics on the walls of the ancient tomb of the petrified pharaoh, he vowed there would be no curse on him like on that other Lord, unless you count his marriage to Lady Tarlington who, when the lost treasure was found, will be dumped faster than that basket in the bulrushes." Melissa Rhodes --------------------------------- The Castles of Dereth Calendar: a tour of the art and architecture of Asheron's Call http://www.lulu.com/content/77264 __________________________________ Do you Yahoo!? Yahoo! Mail - 250MB free storage. Do more. Manage less. http://info.mail.yahoo.com/mail_250
